U.S. Pat. No. 4,123,799 discloses a latching type IGFET sense amplifier which uses a pair of depletion mode IGFETs to isolate semiconductor memory bit line (input) capacitance from the internal terminals of a cross-coupled pair of IGFETs. One problem with this circuit is that the sensitivity thereof is somewhat limited and, accordingly, its use with today's high density and high speed random access memories is marginal. Another problem with this circuit is that the output terminals and the internal terminals of the cross-coupled pair are common. This limits response time and sensitivity.
It would be desirable to have a relatively high sensitivity latching type of sense amplifier (detector) in which the internal terminals of a cross-coupled pair of the amplifier are isolated from the capacitive loading of the input and output terminals.